Cycles Taking 2 Hours to Render One Frame
You should turn off "Square Samples" unless you actually intend to square the number of samples being used (e.g., see https://blenderartists.org/forum/showthread.php?342753-Square-Samples for some insight into why you might want to square the samples).  For previewing purposes, you definitely want to turn it off.  And you'll probably want to bake the simulation so it doesn't have to calculate it every time you switch to a different animation frame.